Monoclonal antibodies used in immunotherapy are produced artificially from a cell clone therefore consist of a single type of immunoglobulin. They are targeted towards specific antigens and bind to the antigens to form a complex. The complex can be recognized and destroyed by phagocytes or used for other diagnostic purposes.
Natural antibodies are proteins made by the B-lymphocytes in response to antigens. Each B-cell makes only one type of antibody. For therapeutic purposes a significant amount of a particular antibody is needed. These are obtained from a culture that gives a one type of antibody, which are called monoclonal antibodies.
CD52 antigens are present on lymphocytes. CD52 monoclonal antibodies bind to CD52 antigens and bring about complement and antibody-dependent cell-mediated cytotoxicity. CD52 monoclonal antibodies are used to treat patients with B-cell chronic lymphocytic leukemia (B-CLL).